Democrats

Registration: At 11 a.m., voters start arriving. They go to a check-in table, where volunteers look at registered voter rolls to see if they are a registered Democratic voter. If they aren't, they can register on the spot to participate in the caucus.

If they are a Republican or belong to another party or are unaffiliated, they can switch party affiliations on the spot and become a Democrat.

Caucus begins: At 11:30 a.m., the number of voters is counted and a decision is made how many voters it will take to win at least one delegate. The caucuses begin and the voters break into groups, representing particular candidates. If the candidate group does not meet the threshold to win at least one delegate, then voters can break off and join other groups.

Some people might like the process of persuading others to join them. Some might not like the idea of being cajoled, or even bullied, into joining particular groups. Kirsten Searer, deputy executive director of the Nevada Democratic Party, said caucus volunteers will try to keep order in case there become some heated moments.

"If they feel like someone is being intimidated, they will step in," said Searer, of the nearly 2,000 recruited volunteers. "But for the most part, it's just good clean fun."

Estimated time needed: Searer predicted the Democratic caucuses would probably take between one hour and two hours, with the process ending by 1 p.m.

Republicans

"The Republican caucuses are nothing like the Democratic caucuses," said Hans Gullickson, Republican state caucus director. There is no clustering. No one knows how you voted, unless you tell them — voting machines will be rented out for the process. And the process is open only to Republicans.

Registration: At 9 a.m., voters can start arriving. At a check-in table, volunteers verify that they are registered Republicans. You cannot register at the caucus. If you didn't registered as a Republican by Dec. 20, you can't participate, Gullickson said.

Organization: Shortly after that, voters elect a caucus chairman and a secretary. Paper ballots are used to select the delegates and alternates who will be attending the state party convention. None of the delegates is bound to any candidate, once elected, he said. However, most of them declare support for one of the candidates.

Presidential poll: After the delegates are picked, using paper ballots, voters are encouraged to vote in a straw poll, using voting machines.

Estimated time needed: Gullickson said it would probably be over in 30 to 45 minutes.